Many studies have shown that stress and other emotional factors increase the risk of disease, reduce performance and productivity and severely restrict the quality of life. To this end, the medical communities around the world continually seek remedies and preventive plans. Recently, a focus on the self-regulation of systems within the body has led to research in the areas of increasing performance and facilitating recovery from numerous health challenges. Such research has suggested a causal link to, for example, enhanced academic performance, communication and listening skills, faster reaction times and better coordination.
In the last 25 years, a variety of new techniques have been introduced as alternatives to more traditional psychotherapies or pharmaceutical interventions for improving mental and/or emotional imbalances, reducing stress and improving performance. Devices have been designed for this purpose, some portable and some not. Portable devices capable of measuring heart rate are known for use in monitoring physical fitness activities. These devices tend to use heart rate sensors based on electrocardiogram (ECG) detectors, and are either embedded in a chest strap or use finger contacts on a watch. Other portable devices record a higher resolution ECG for the purpose of medical assessment or diagnosis (e.g., Halter Recorders). Thus, the two most commonly-used portable devices for heart-rate related measurements fall into two general categories: devices which track the average heart rate for physical fitness (HR monitors), and devices recording the ECG for the purposes of medical assessment, diagnosis or research.
The first category, which tends to use a wireless chest strap with an embedded ECG pickup, detects and averages the heart beat while displaying it on a watch or stopwatch like module. The second category are so-called Halter Recorders, and tend to use electrodes taped to the skin and tape or solid state media to record a full electrocardiogram over a period of time for later medical analysis. That is, there tends to be little feedback during the recording session. However, neither category of device is designed to improve physiological coherence or autonomic balance.